• Journal of Korean Society of Rural Planning
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• v.25 no.3
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• pp.129-139
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• 2019

The purpose of this study is to monitor the long-term vegetation change of the village complementary forest after restoration. Based on the monitoring in 2010, six years after the restoration project in 2004, the monitoring of the complementary forest in Dubang village in 2019 after 9 years was conducted. This study identifies the change of species diversity and structure, growth, vegetation coverage, structural quality etc. and succession through long-term monitoring. For this, field survey was conducted in 2003 and 2010, 2019. The results demonstrate significant increase of species diversity and multi-layer structure and progress of natural succession. Overall, Part I is considered to be a quasi-natural complementary village forest, which has a natural balance between natural vegetation that have remained in nature for a long time and anthropogenic vegetation, revealing the coexistence of nature and humanity. It means ecological structure and function have improved. Part II should be restored to the lost part and adaptive management rather than excessive management should be carried out to leave natural succession.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.4
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• pp.249-256
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• 1997

To identify the long-term influence of acid rain treatment on tree growth, acid rain of various composition (pH 2.0, pH 4.0 and pH 5.6 as control) was applied to several landscape trees for five months (April through August, 1991). Tree height, pH values and $Al^{3+}$ concentration in soil were investigated. Acid rain treatments seemed to promote height growth in the first year (1991), but have become an inhibiting factor over five years. All of coniferous species and most broad-leaved species, except Acer ginnala, showed opposite trends in height responses to acid rain treatments between the first (1991) and last (1996) year. In contrast, Acer ginnala showed similar trends to acid rain treatments in the height growth between 1991 and 1996. This result suggested that Acer ginnala has a characteristic adapability to acid rain stress. pH values of surface soil were lower than those of 30 cm soil depth. This fact suggested that acid rain treatments made surface soil acidic condition. In addition, physiological characteristics (photosynthesis, stomatal condition and biomass) have to be investigated to identify the relationship between long-term effects of $AL^{3+}$ concentration and growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.534-541
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• 2002

The use of triorganotins as insecticides, bacteriocides, and antifouling agents has increased dramatically over the past 30 years, In this paper, to evaluate the acute and chronic toxicity effects of various triorganotins (TBTO, TBTE, CTPT, TBTCI) on the growth of microalgae, Skeletonema costatum, we carried out the short term and long term experiments, respectively. In the short-term experiments, the growth of S. costatum was inhibited by the various triorganotins in the dose dependent manners, but recovered by the time laps. The growth inhibition of triorganotins were decreased in the groups with higher initial cell density. These data were resulted from the dilution effect and the biodegradation of triorganotins by the microalgae. In the long-term experiments, S. costatum died completely at the 1 $\mu$g/L of TBTP and CTPT, but didn't in short-term experiments. The facts suggest that the toxicity of the chronic exposure of triorganotins should be increased in the natural sea water with low phytoplankton density.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.917-922
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• 2002

We investigated the long term effects of Sopungsungi-won (SP), a Korean traditional formula used for senile constipation and diabetes mellitus, on the development of diabetic nephropathy (DN) in Zucker diabetic fatty (ZDF) rats. ZDF rats were fed regular laboratory chow mixed with SP or rosiglitazone (RSG) for an 8-week period. Kidney hypertrophy was developed with increasing plasma glucose level, and glomerular hypertrophy was improved by 22% and 45% in SP- and RSG-treated rats, respectively. Urinary glucose and albumin excretions were also significantly lower in SP-treated rats than in ZDF control rats. Activation of the mitogen-activated protein kinase (MAPK)-transforming growth factor ${\beta}1$ (TGF ${\beta}1$)-fibronectin pathway in kidney, responsible for glomerular dysfunction, was markedly blunted by SP treatment in a dose dependent manner. Our findings, for the first time, provide strong evidence that long-term administration of SP formula prevents the development and progression of DN in ZDF rats. Human trials are needed to confirm these experimental results.

• Korean Journal of Health Education and Promotion
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• v.32 no.3
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• pp.97-107
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• 2015

Objectives: The current study aims to examine whether the influence of National Long-term Care Insurance(NLCI) on the quality of life(QoL) trajectory of older adults with disabilities is more positive than its influence on those without disabilities. Methods: Sample consisted of 5,362 elderly aged 65 and over who participated in the Korean Welfare Panel Study from Wave1 to Wave7. Data were analyzed using latent growth curve modeling. Results: Major findings are as follows. (1) Before the NLCI, the trajectories of QoL between older adults with disabilities and those without were same. (2) After the NLCI, elders with disabilities showed lower levels of QoL at the beginning, but the gaps gradually decreased with time. These results indicate that the implementation of NLCI more positively affected elders with disabilities than those without disabilities. Conclusions: These results suggest that the NLCI functions properly as one of social security nets to cope with the needs of older adults with disabilities. In conclusion, it is critical to develop a sustainable NLCI system to enhance the QoL of older adults with disabilities.

• Korean Journal of Adult Nursing
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• v.29 no.3
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• pp.278-289
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• 2017

Purpose: This study was designed to investigate whether there were differences among three oral care protocols on participants' oral health status (oral status, dry mouth, halitosis, saliva pH, microorganism growth in oral cavity) and tooth stain. The three protocols were: 1) oral solution of 4% normal saline, 2) 0.1% Chlorhexidine and 3) Tantum. Methods: A nonequivalent control group pretest-posttest design was utilized. A total of 55 elderly patients residing at long-term care facilities(19 in the 4% normal saline group, 17 in the 0.1% Chlorhexidine group, 19 in the Tantum group) received oral care daily for four weeks. Data were analyzed using SPSS/WIN 22.0 program. Results: The halitosis (${\chi}^2=10.71$, p=.005) and saliva pH (${\chi}^2=6.84$, p=.033) scores were significantly improved after the oral care with 4% normal saline. Conclusion: These findings indicate that if elderly patients in long-term care facilities have complaint of the discomfort of using Chlorhexidine or Tantum, 4% normal saline is as effective at the other two. This can also be cost effective as there were no differences among the protocols in oral status, dry mouth, tooth stain or microorganism growth in oral cavity.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.10
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• pp.389-398
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• 1985

Recently maximum power demand of our country has become to be under the great in fluence of electric cooling and air conditioning demand which are sensitive to weather conditions. This paper presents the technique and algorithm to forecast the long-term maximum power demand considering the characteristics of electric power and weather variable. By introducing a weather load model for forecasting long-term maximum power demand with the recent statistic data of power demand, annual maximum power demand is separated into two parts such as the base load component, affected little by weather, and the weather sensitive load component by means of multi-regression analysis method. And we derive the growth trend regression equations of above two components and their individual coefficients, the maximum power demand of each forecasting year can be forecasted with the sum of above two components. In this case we use the coincident dry bulb temperature as the weather variable at the occurence of one-day maximum power demand. As the growth trend regression equation we choose an exponential trend curve for the base load component, and real quadratic curve for the weather sensitive load component. The validity of the forecasting technique and algorithm proposed in this paper is proved by the case study for the present Korean power system.

• Korean Journal of Occupational Health Nursing
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• v.31 no.4
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• pp.187-197
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• 2022

Background: This study explores the pathways of nurse turnover in long-term care hospitals (LTCHs) and its underlying conditions in Korea. Although the factors of staying or leaving of nurses in LTCHs have been reported, few studies have examined the trajectory and conditions of nurses staying in and leaving LTCHs. Methods: A qualitative study design with a grounded theory approach was conducted. Data were collected in one-to-one interviews. Purposive and theoretical sampling led to the inclusion of 20 registered nurses from 15 LTCHs in South Korea. Results: Seeking work-life balance was the core category of the nurses' turnover pathway. The consequences of the nurses' turnover pathway were categorized into three groups: thriving, surviving, and leaving. Thriving nurses found meaning in their work, fostered good relationships, and saw opportunities for growth. Surviving nurses were enduring their jobs in LTCHs, having a work-life balance, and supportive nursing leaders. Leaving group nurses wished to leave LTCHs due to a lack of professional growth, unappealing work, continued conflict, and social stigma. Conclusion: This study provided the trajectory and conditions for nurses to enter, stay, move, or leave. Understanding the pathways for staying or leaving can be used as a strategy for successful retention of registered nurses in LTCHs.

• Journal of Technology Innovation
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• v.31 no.2
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• pp.59-82
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• 2023

The purpose of this research is to conduct the empirical analysis of the short- and long-term causal relationship between public R&D investment, corporate R&D investment, and university R&D investment on economic growth in Korea. To this end, based on the time series data from 1976 to 2020, a causality test was conducted through the unit root test, cointegration test, and vector error correction model (VECM). As a result, it was found that there is a long-run equilibrium relationship between economic growth in Korea, public R&D investment, corporate R&D investment, and university R&D investment, in which a causal relationship exists in the long run. Also, while public R&D investment has a short-term effect on economic growth, corporate and university R&D investment does not have a short-term effect on economic growth. In addition, the results shows that there is a bidirectional causal relationship between economic growth and public R&D investment, corporate R&D investment and public R&D investment, and university R&D investment and public R&D investment in the short term. Through this research, it was empirically found that a highly mutual relationship exists between public R&D investment, corporate R&D investment, university R&D investment and economic growth. In order to increase the ripple effect of R&D investment on economic growth in the future, R&D investment between universities and corporations should be mutually promoted, and R&D investment by corporations should have a positive effect on public R&D investment so that public R&D investment can contribute to future economic growth.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.75-83
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• 2021

Variation in demand, natural resource availability, and technological advancement within a country are the main reasons for necessitating export and import activities between nations. Accordingly, this paper aims to analyze the effect of economic openness on Multifactor Productivity (MFP) in selected Asian countries (Vietnam, Thailand, The Philippines, Indonesia, Cambodia, China, Japan, Malaysia, South Korea, and Singapore) based on data for the period 1990-2018. The analysis conducted in the study employed the panel ARDL approach based on the estimation by Pooled Mean Group (PMG), Mean Group (MG), and Dynamic Fixed Effect (DFE). The Hausman test conducted indicates that the PMG estimation is better than that of MG and DFE since it has a higher variability value than the significance value. The results revealed that economic openness is able to elicit significant and positive effects on short-term and long-term MFP growth. In addition, the study established that other variable, such as the number of schooling years, are also able to produce a positive and significant effect on MFP growth in the long term. Since economic openness can impact MFP growth, every country should thus increase its export activities through more capital and worker inputs that will stimulate greater production.